The filigree process is an ancient technique done entirely by hand without the help of any particular machine and following exactly the traditional system.
Before the filigree manufacturing, we illustrate the various process phases that bring the raw metal to become a great value piece of art. The phases are divided in 5: metal melting, lamination, wire drawing, twisting, filigree manufacturing and polishing.
The first part of the production consists of submitting the metal, placed in a fire clay melting pot, to a high thermal treatment ( until the melting point).
Gold being a pliable metal, it shouldn’t be used alone for jewellery manufacturing. It’s for this reason that the noble metal is always alloyed with other metals, that give it greater hardness. These competent combinations, that give the metal different colors are called alloys, and for this union we obtain various type of gold: yellow gold, white gold, pink gold. Once the metal has been melted in the melting pot with the blowpipe or pedal pipe, it is poured into an ingot mould and cooled down. So we pass the second process step.
The cooled metal bar is extracted from the ingot mould and it goes in a rolling mill so the thickness can be reduced every time more. The rolling mill is made up of two overlapping steel or cast iron cylinders that turn in the opposite direction. Then the bar is passed in some groovies that progressively become smaller, reducing in this way the thickness of the wire to one millimeter.During this step it is essential to fire again the wire in order to give it a new resistance to the stretching. Once we obtain this thin wire we proceed with the third process.
This phase consists of obtaining a thinner reduction of the wire, inserting its in a steel die or stone plate with dimensions always smaller, until we obtain the desired thickness. Also during this procedure the wire needs to be fired in order to reinvigorate and become elastic again. The wire’s thickness can arrive sometimes at 0,15 mm. All these phases we have analyzed are typical for all jewellery manufacturing, while the last one is fundamental and stands out filigree from other manufacturing.
This process consists of twisting three wires gliding them on a small wood board, and creating a long plait.This phase has to be done very carefully because the twist must be uniform in all its length. As the lamination the twist needs to be fired again.
There are two way of working the Sardinian filigree:
the first is called “per Day”: it consists of making the structure of the jewellery, then filling it up with a wire spiral rolled, welding it at the end.
The second is called “per Night”: it consists of using a support in which the retwisted wire is welded in different shapes.
The last part of the working is the polishing, that is done to eliminate every trace of residue and opacity, giving to the metal a shiny and brilliant colour.